TC gears vs diff ring/pinion for regear?

[SHREDwagon]

There are plenty of us wheeling a lot harder than the overland crowd running Korean gears that work just fine

Wheeling vs longevity = different argument. If one was building for short distance wheeling, sure. Post up when you have 250k miles on your made in Korea gears.

Does that mean you don't buy RCV axles because they are made in America?

I have RCV's in the front, but swapped back to OEM for a trip to AK /YK. No issues with either, but prefer OEM for distance.

 

[cruiseroutfit]

A couple of things to note with that

1. You have to remove the thirds which is going to be a more labor intensive process then a transfer case
2. Don't forget to factor in the front axle rebuild since you have to extract the shafts to get the 3rds out (add an extra $200 to the cost you quoted) now we are in the range of TC gears.
3. While you will get a low range reduction by re-gearing the diffs, you will get more reduction by re-gearing the low range side of the TC.

Great points.

One needs to consider what rebuilds they are doing on their axles and/or need to do. If you've freshly serviced your axles the t-case gears are a total win. If you're already doing axle service then the extra effort to pull the 3rds is pretty minimal and subsequently brings the overall effort down.

 

[Tools R Us]

Wheeling vs longevity = different argument. If one was building for short distance wheeling, sure. Post up when you have 250k miles on your made in Korea gears.
...

Kinda, maybe, the stress that wheeling puts on gears is a good test, ages them in shorter term. If they can take that type of loads without shedding and run smooth, are likely to take touring type duty long term.

So, your gears have 250k mi on them? That is a pretty good run for aftermarket gears. What brand are they?

 

[Qball]

Ideal setup would be lower Diff gears, lower low range and over drive high range T case gear. Best of both worlds! We can achieve close to 50% slower craw speed!

 

[cruiseroutfit]

Ideal setup would be lower Diff gears, lower low range and over drive high range T case gear. Best of both worlds! We can achieve close to 50% slower craw speed!

That is a interesting way to look at it. Cost aside it would get one quite low final drive.

 

[Qball]

That is a interesting way to look at it. Cost aside it would get one quite low final drive.

And normal highway rpm.

 

[ReformedJeeper]

Wheeling vs longevity = different argument. If one was building for short distance wheeling, sure. Post up when you have 250k miles on your made in Korea gears.

Why would a gearset fail when you're just driving dirt roads? Seriously, do you think the metallurgy is that bad that a Korean gear will fail just over time? Many of Yukon's gears come out of Korea and they aren't failing at high rates. While I agree in principle that Toyota gears are a good quality, I seriously doubt they are the only good gears around. Also, I have 250k on my cruiser, who knows if it will be alive in another 250k.

You will most likely have bearing problems long before you wear out your R&P. Even in cheap domestics with a lot of miles and never a gear oil change do you see worn out gears, and I'm sure ford and chevy don't take quality as seriously as toyota.

I think you've let your Mud OCD go to far. As @nukegoat would say, if you don't put in toyota gears you'll blow a head gasket.

 

[iptman]

And normal highway rpm.

... depending on tire size.

I went with both the UD high and lower low gear in the transfer case because I wanted to retain factory RPM with 315/75/16 tires in high range and figured since the Tcase would be opened anyway just do the low at the same time. @OTRAMM did the work and I'm very happy with the outcome.

 

[1973Guppie]

While the transfer case reduction gears are great for slow crawling, hill decents, and steep climbs in offroad, the benefit is limited to low-range only. I look at these as Icing on the cake, as a compliment to proper diff gearing. Not as a substitute. If you are running 33” + on stock gearing you can and WILL benefit from changing the diff gears in High and low range. Running larger tires has the same effect as gearing higher, by reducing RPMs below the ideal operating range. What this does is cause overdrive to become less useful as the vehicle is often down shafting, trying to stay at proper RPM’s, thus running even higher RPMS. This is bad for economy, performance, acceleration, wear & tear etc. So regearing your diffs gets you where you should be in Low & High Range, for offroad and Highway use, the transfercase only benefits for offroad and lowrange. Long story short, if you can afford to, do both. If not, do Diff gears. As for the debate on strength between different ratios, while there is theoretically some compromise, the benefits of the proper gearing far offset them. Additionally a new diff with 4.88 setup properly is going to hold up better than a 4.10 diff with 250k on it.

I agree with this, well put. I did the low tc gears and swapped to 4.88's at the same time. Shift points were greatly improved and overall driveability improved. The lower gears help alot slowing this pig down when in low, I used to have to mash the brakes and now I just let it roll.

 

[Qball]

I really enjoy my rubber over drive and if need power I’ll go turbo or SC route but I don’t find drivability that bad with stock 4.11 and with 25% lowerlow gear I am still ~10-15% slower than stock tire in low. This so far at been a very good combo for both on the road and off-road.

If my 80 is on dirt only then I would throw in the 5.29, with lower case gear and 5.29 it crawls sooooooo nice and slow with 35s. I tried someone’s 80 with that combo and it went up a big curb nice and slow with no gas, with 4.11 and low gear I still have to give it a little gas.

 

[Malleus]

Are Nitro gears any good?

I can't say. My experience is only with OEM designs.

 

[White Stripe]

I can't say. My experience is only with OEM designs.

Do you have any torque failure specs for a ring and pinion set of say 3.70 or 4.11 gears vs 5.29s for toyota differentials?

 

[Malleus]

Actually, no. The OEMs don't keep that kind of data. If they wanted it, they'd go the the off-road racing community and put it together from their experience.

The kind of OEM data available would be design limits for given combinations. Unless there was a specific failure in production models, within a (short) given period of time, you probably wouldn't find that kind of data anywhere. Even then, you'd have to know the lead engineer on the campaign, and you'd have to convince him to share that data with you. Neither is very likely.

What are you trying to understand?

 

[White Stripe]

Actually, no. The OEMs don't keep that kind of data. If they wanted it, they'd go the the off-road racing community and put it together from their experience.

The kind of OEM data available would be design limits for given combinations. Unless there was a specific failure in production models, within a (short) given period of time, you probably wouldn't find that kind of data anywhere. Even then, you'd have to know the lead engineer on the campaign, and you'd have to convince him to share that data with you. Neither is very likely.

What are you trying to understand?

ARB may have it. I was just curious what the numbers were. But I don't think arb would share it either since they use that data to build their lockers. Once in a while you will see such data shared such as when the longfields first came out they published torque failure ratings vs oem birfield ratings to show how superior the product was vs oem birfs.

 

[just differentials]

I can't say. My experience is only with OEM designs.

Nitro Gears are exceptional. Special lapping process that makes them setup super consistently & run on the quiet side. We & many other shops around the nation prefer to use Nitro Gear

 

[lumbee1]

If the TC gears came in 1.15 underdrive, I would install them over the 4.88 diff gears.

 

[cruiseroutfit]

If the TC gears came in 1.15 underdrive, I would install them over the 4.88 diff gears.

1.15, 1.20, etc. Some discussion on our planning here:
YWST: Low Range T-Case Gear Sets for the 1980-2007 Cruisers

 

[lumbee1]

1.15, 1.20, etc. Some discussion on our planning here:
YWST: Low Range T-Case Gear Sets for the 1980-2007 Cruisers

I am looking for high range and low range TC gears. 1.10 would be almost back to factory for high range, but 1.15 would be a bit more peppy on the road.

 

[junior80]

I am looking for high range and low range TC gears. 1.10 would be almost back to factory for high range, but 1.15 would be a bit more peppy on the road.

How did you go with this @lumbee1 i’m about to order the high tang underdrive and low range reduction gears from cruiser outfitters

 

[junior80]

High tang? Maybe I meant high range. I don’t know if they have any high tang